Some people believe that Donald Trump is a Democratic mole who is in the Republican presidential race to scare away voters from the GOP and torpedo otherwise-promising Republican contenders by getting them to co-sign crazy. Those who believe that Trump is a Democrat in Republicans’ clothing will wince at the question that NBC News’ Kasie Hunt put to Wisconsin Gov. Scott Walker this week at the Iowa State Fair: “Do you think birthright citizenship should be ended?”
Ruben Navarrette: Candidates easily fall into the Trump trap